α-Ni(OH)2制备纤维状Ni纳米材料

α-Ni(OH)2 with hydrotalcite-like structure was prepared by precipitation of nickel acetate and sodium carbonate aqueous solution with the mediation of ethylene glycol at 393 K. Calcination of this precursor at 573-1073 K yielded nickel oxides having diameter of 3-8 nm with inter-layered structure. Hydrogen reduction of the NiO samples formed metallic nickel with fibrous-like morphology. These novel Ni materials showed much higher catalytic activities for the decomposition of methane to hydrogen and carbon nanofibers, with the carbon yield of 498 g C/g Ni. The changes in crystalline size and morphology of Ni during reduction and methane decomposition are well studied by XRD and TEM. The Ni crystallines departed from the fibrous structures and gradually aggregated into particles, which is stabilized at the critical size of 17–18 nm when exposed to the reaction of methane decomposition